1. Chapter 3
Epithelial tissues

2. Overview 4 main types of tissues in the human body What is a tissue?
Epithelial tissue
Connective tissue
Muscular tissue
Nervous tissue

3. Structure and Function
Epithelial tissue provides coverings and linings
provide protection
Allow for diffusion, filtration and osmosis
Secretion, transport, absorption

4. Basic structure Epithelial cells are packed close together
Little intercellular material between them
Form continuous sheets with no blood vessels
That is why epithelial tissues provide good coverings

5. Shape and Arrangement
Epithelial cells are classified according to the shape of the shell and how they are arranged

6. Shape of Cells Squamous: flat and scale-like Cuboidal: cube shaped
Columnar: higher than wide
Transitional: varying shapes that can stretch

7. Arrangement of Cells Simple: single layer of cells of the same shape
Stratified: many layers of cells, named for the shape of the cells in the outer layer
Pseudostratified: appears to be layered, but is not

8. Attachment Epithelial tissues attach to other tissues
A basement membrane forms at the bottom of the tissue
Generally this then attaches to a connective tissue

10. Simple Squamous Epithelium
Single layer, very thin
Substances can easily pass through
Diffusion of gases occurs easily
Example: alveoli (tiny air sacs in lungs) and the linings of blood vessels and lymphatic tissue

12. Stratified Squamous Epithelium
Several layers of closely packed cells
Protection
Examples; epidermis, lining of mouth

14. Simple Columnar Single layers Higher than wide (columns)
specialize in absorption
Open spaces; goblet cells
Goblet cells make mucus

16. Simple Cuboidal Does not form coverings Forms clusters of tubules
Tubules secrete
Example; gland tissue and the secretion of hormones

18. Transitional epithelium
Several layers and has the ability to stretch
Bladder tissue
When cells stretch, they flatten out

20. Psuedostratified Appears to be two layers thick, but is not
Cilia extend from from cells
Allow rapid movement of substances
Line the trachea (rapid removal of dust)

21. Make a chart to study List category of tissues List each type
Describe it’s structure
List it’s function
Give one or two examples of where it is located in the human body
Use the chart to make a matching quiz for yourself